PROJECT SUMMARY The Microscopy Core and Flow Cytometry (Core B) will provide expertise and service related to standard electron microscopy (EM), as well as fluorescent microscopy and flow cytometry as needed by each of the three project components. Such a centralized facility for specimen preparation and imaging will be cost- effective and facilitate more orderly and efficient use of the EM and fluorescent microscope resources to complete the proposed projects in a timely fashion. The requested budget is modest with a 50% salary for a microscopy/imaging lab manager and as well as a research technician and 50% service contract for the EM and fluorescent microscopes. A new addition is 24% time for a flow cytometry expert. The specific functions of the core will include: (1) specimen preparation for electron microscopy; (2) imaging of viruses, recombinant particles, and their complexes with ?carbohydrate and antibodies, reconstituted lipid vesicles to evaluate purity and concentration; (3) imaging of fecal samples from calicivirus infected animals and humans; (4) imaging of stained thin sections of virus infected cells; (5) immuno-electron microscopy; (6) data acquisition, sharing, and archiving; (7) scheduling and day-to-day EM maintenance; (8) specimen preparation for fluorescent microscopy; (9) flow cytometry to obtain quantitative data on virus-infected cells and on PBMCs collected from norovirus-infected individuals (10) scheduling and day-to-day maintenance of the microscopes and flow cytometers. The Core Directors and Associate Director will coordinate all aspects of the Microscopy and Flow Cytometry Core.